[HMM 01/16] mm/memory/hotplug: add memory type parameter to arch_add/remove_memory

Jérôme Glisse
2017-04-05T20:41:06Z

When hotpluging memory we want more information on the type of memory.
This is to extend ZONE_DEVICE to support new type of memory other than
the persistent memory. Existing user of ZONE_DEVICE (persistent memory)
will be left un-modified.

Signed-off-by: Jérôme Glisse <jglisse@redhat.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Rich Felker <dalias@libc.org>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
---
arch/ia64/mm/init.c | 36 +++++++++++++++++++++++++++++++++---
arch/powerpc/mm/mem.c | 37 ++++++++++++++++++++++++++++++++++---
arch/s390/mm/init.c | 16 ++++++++++++++--
arch/sh/mm/init.c | 35 +++++++++++++++++++++++++++++++++--
arch/x86/mm/init_32.c | 41 +++++++++++++++++++++++++++++++++++++----
arch/x86/mm/init_64.c | 39 +++++++++++++++++++++++++++++++++++----
include/linux/memory_hotplug.h | 24 ++++++++++++++++++++++--
include/linux/memremap.h | 2 ++
kernel/memremap.c | 5 +++--
mm/memory_hotplug.c | 4 ++--
10 files changed, 215 insertions(+), 24 deletions(-)

diff --git a/arch/ia64/mm/init.c b/arch/ia64/mm/init.c
index 06cdaef..c910b3f 100644
--- a/arch/ia64/mm/init.c
+++ b/arch/ia64/mm/init.c
@@ -645,20 +645,36 @@ mem_init (void)
}

#ifdef CONFIG_MEMORY_HOTPLUG
-int arch_add_memory(int nid, u64 start, u64 size, bool for_device)
+int arch_add_memory(int nid, u64 start, u64 size, enum memory_type type)
{
pg_data_t *pgdat;
struct zone *zone;
unsigned long start_pfn = start >> PAGE_SHIFT;
unsigned long nr_pages = size >> PAGE_SHIFT;
+ bool for_device = false;
int ret;

+ /*
+ * Each memory_type needs special handling, so error out on an
+ * unsupported type. In particular, MEMORY_DEVICE_UNADDRESSABLE
+ * is not supported on this architecture.
+ */
+ switch (type) {
+ case MEMORY_NORMAL:
+ break;
+ case MEMORY_DEVICE_PERSISTENT:
+ for_device = true;
+ break;
+ default:
+ pr_err("hotplug unsupported memory type %d\n", type);
+ return -EINVAL;
+ }
+
pgdat = NODE_DATA(nid);

zone = pgdat->node_zones +
zone_for_memory(nid, start, size, ZONE_NORMAL, for_device);
ret = __add_pages(nid, zone, start_pfn, nr_pages);
-
if (ret)
printk("%s: Problem encountered in __add_pages() as ret=%d\n",
__func__, ret);
@@ -667,13 +683,27 @@ int arch_add_memory(int nid, u64 start, u64 size, bool for_device)
}

#ifdef CONFIG_MEMORY_HOTREMOVE
-int arch_remove_memory(u64 start, u64 size)
+int arch_remove_memory(u64 start, u64 size, enum memory_type type)
{
unsigned long start_pfn = start >> PAGE_SHIFT;
unsigned long nr_pages = size >> PAGE_SHIFT;
struct zone *zone;
int ret;

+ /*
+ * Each memory_type needs special handling, so error out on an
+ * unsupported type. In particular, MEMORY_DEVICE_UNADDRESSABLE
+ * is not supported on this architecture.
+ */
+ switch (type) {
+ case MEMORY_NORMAL:
+ case MEMORY_DEVICE_PERSISTENT:
+ break;
+ default:
+ pr_err("hotplug unsupported memory type %d\n", type);
+ return -EINVAL;
+ }
+
zone = page_zone(pfn_to_page(start_pfn));
ret = __remove_pages(zone, start_pfn, nr_pages);
if (ret)
diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c
index 5f84433..0933261 100644
--- a/arch/powerpc/mm/mem.c
+++ b/arch/powerpc/mm/mem.c
@@ -126,14 +126,31 @@ int __weak remove_section_mapping(unsigned long start, unsigned long end)
return -ENODEV;
}

-int arch_add_memory(int nid, u64 start, u64 size, bool for_device)
+int arch_add_memory(int nid, u64 start, u64 size, enum memory_type type)
{
struct pglist_data *pgdata;
- struct zone *zone;
unsigned long start_pfn = start >> PAGE_SHIFT;
unsigned long nr_pages = size >> PAGE_SHIFT;
+ bool for_device = false;
+ struct zone *zone;
int rc;

+ /*
+ * Each memory_type needs special handling, so error out on an
+ * unsupported type. In particular, MEMORY_DEVICE_UNADDRESSABLE
+ * is not supported on this architecture.
+ */
+ switch (type) {
+ case MEMORY_NORMAL:
+ break;
+ case MEMORY_DEVICE_PERSISTENT:
+ for_device = true;
+ break;
+ default:
+ pr_err("hotplug unsupported memory type %d\n", type);
+ return -EINVAL;
+ }
+
pgdata = NODE_DATA(nid);

start = (unsigned long)__va(start);
@@ -153,13 +170,27 @@ int arch_add_memory(int nid, u64 start, u64 size, bool for_device)
}

#ifdef CONFIG_MEMORY_HOTREMOVE
-int arch_remove_memory(u64 start, u64 size)
+int arch_remove_memory(u64 start, u64 size, enum memory_type type)
{
unsigned long start_pfn = start >> PAGE_SHIFT;
unsigned long nr_pages = size >> PAGE_SHIFT;
struct zone *zone;
int ret;

+ /*
+ * Each memory_type needs special handling, so error out on an
+ * unsupported type. In particular, MEMORY_DEVICE_UNADDRESSABLE
+ * is not supported on this architecture.
+ */
+ switch (type) {
+ case MEMORY_NORMAL:
+ case MEMORY_DEVICE_PERSISTENT:
+ break;
+ default:
+ pr_err("hotplug unsupported memory type %d\n", type);
+ return -EINVAL;
+ }
+
zone = page_zone(pfn_to_page(start_pfn));
ret = __remove_pages(zone, start_pfn, nr_pages);
if (ret)
diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c
index bf5b8a0..20d7714 100644
--- a/arch/s390/mm/init.c
+++ b/arch/s390/mm/init.c
@@ -153,7 +153,7 @@ void __init free_initrd_mem(unsigned long start, unsigned long end)
#endif

#ifdef CONFIG_MEMORY_HOTPLUG
-int arch_add_memory(int nid, u64 start, u64 size, bool for_device)
+int arch_add_memory(int nid, u64 start, u64 size, enum memory_type type)
{
unsigned long zone_start_pfn, zone_end_pfn, nr_pages;
unsigned long start_pfn = PFN_DOWN(start);
@@ -162,6 +162,18 @@ int arch_add_memory(int nid, u64 start, u64 size, bool for_device)
struct zone *zone;
int rc, i;

+ /*
+ * Each memory_type needs special handling, so error out on an
+ * unsupported type.
+ */
+ switch (type) {
+ case MEMORY_NORMAL:
+ break;
+ default:
+ pr_err("hotplug unsupported memory type %d\n", type);
+ return -EINVAL;
+ }
+
rc = vmem_add_mapping(start, size);
if (rc)
return rc;
@@ -205,7 +217,7 @@ unsigned long memory_block_size_bytes(void)
}

#ifdef CONFIG_MEMORY_HOTREMOVE
-int arch_remove_memory(u64 start, u64 size)
+int arch_remove_memory(u64 start, u64 size, enum memory_type type)
{
/*
* There is no hardware or firmware interface which could trigger a
diff --git a/arch/sh/mm/init.c b/arch/sh/mm/init.c
index 7549186..f37e7a6 100644
--- a/arch/sh/mm/init.c
+++ b/arch/sh/mm/init.c
@@ -485,13 +485,30 @@ void free_initrd_mem(unsigned long start, unsigned long end)
#endif

#ifdef CONFIG_MEMORY_HOTPLUG
-int arch_add_memory(int nid, u64 start, u64 size, bool for_device)
+int arch_add_memory(int nid, u64 start, u64 size, enum memory_type type)
{
pg_data_t *pgdat;
unsigned long start_pfn = PFN_DOWN(start);
unsigned long nr_pages = size >> PAGE_SHIFT;
+ bool for_device = false;
int ret;

+ /*
+ * Each memory_type needs special handling, so error out on an
+ * unsupported type. In particular, MEMORY_DEVICE_UNADDRESSABLE
+ * is not supported on this architecture.
+ */
+ switch (type) {
+ case MEMORY_NORMAL:
+ break;
+ case MEMORY_DEVICE_PERSISTENT:
+ for_device = true;
+ break;
+ default:
+ pr_err("hotplug unsupported memory type %d\n", type);
+ return -EINVAL;
+ }
+
pgdat = NODE_DATA(nid);

/* We only have ZONE_NORMAL, so this is easy.. */
@@ -516,13 +533,27 @@ EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);
#endif

#ifdef CONFIG_MEMORY_HOTREMOVE
-int arch_remove_memory(u64 start, u64 size)
+int arch_remove_memory(u64 start, u64 size, enum memory_type type)
{
unsigned long start_pfn = PFN_DOWN(start);
unsigned long nr_pages = size >> PAGE_SHIFT;
struct zone *zone;
int ret;

+ /*
+ * Each memory_type needs special handling, so error out on an
+ * unsupported type. In particular, MEMORY_DEVICE_UNADDRESSABLE
+ * is not supported on this architecture.
+ */
+ switch (type) {
+ case MEMORY_NORMAL:
+ case MEMORY_DEVICE_PERSISTENT:
+ break;
+ default:
+ pr_err("hotplug unsupported memory type %d\n", type);
+ return -EINVAL;
+ }
+
zone = page_zone(pfn_to_page(start_pfn));
ret = __remove_pages(zone, start_pfn, nr_pages);
if (unlikely(ret))
diff --git a/arch/x86/mm/init_32.c b/arch/x86/mm/init_32.c
index c68078f..811d631 100644
--- a/arch/x86/mm/init_32.c
+++ b/arch/x86/mm/init_32.c
@@ -826,24 +826,57 @@ void __init mem_init(void)
}

#ifdef CONFIG_MEMORY_HOTPLUG
-int arch_add_memory(int nid, u64 start, u64 size, bool for_device)
+int arch_add_memory(int nid, u64 start, u64 size, enum memory_type type)
{
struct pglist_data *pgdata = NODE_DATA(nid);
- struct zone *zone = pgdata->node_zones +
- zone_for_memory(nid, start, size, ZONE_HIGHMEM, for_device);
unsigned long start_pfn = start >> PAGE_SHIFT;
unsigned long nr_pages = size >> PAGE_SHIFT;
+ bool for_device = false;
+ struct zone *zone;
+
+ /*
+ * Each memory_type needs special handling, so error out on an
+ * unsupported type. In particular, MEMORY_DEVICE_UNADDRESSABLE
+ * is not supported on this architecture.
+ */
+ switch (type) {
+ case MEMORY_NORMAL:
+ break;
+ case MEMORY_DEVICE_PERSISTENT:
+ for_device = true;
+ break;
+ default:
+ pr_err("hotplug unsupported memory type %d\n", type);
+ return -EINVAL;
+ }
+
+ zone = pgdata->node_zones +
+ zone_for_memory(nid, start, size, ZONE_HIGHMEM, for_device);

return __add_pages(nid, zone, start_pfn, nr_pages);
}

#ifdef CONFIG_MEMORY_HOTREMOVE
-int arch_remove_memory(u64 start, u64 size)
+int arch_remove_memory(u64 start, u64 size, enum memory_type type)
{
unsigned long start_pfn = start >> PAGE_SHIFT;
unsigned long nr_pages = size >> PAGE_SHIFT;
struct zone *zone;

+ /*
+ * Each memory_type needs special handling, so error out on an
+ * unsupported type. In particular, MEMORY_DEVICE_UNADDRESSABLE
+ * is not supported on this architecture.
+ */
+ switch (type) {
+ case MEMORY_NORMAL:
+ case MEMORY_DEVICE_PERSISTENT:
+ break;
+ default:
+ pr_err("hotplug unsupported memory type %d\n", type);
+ return -EINVAL;
+ }
+
zone = page_zone(pfn_to_page(start_pfn));
return __remove_pages(zone, start_pfn, nr_pages);
}
diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
index 7eef172..6c0b24e 100644
--- a/arch/x86/mm/init_64.c
+++ b/arch/x86/mm/init_64.c
@@ -641,15 +641,33 @@ static void update_end_of_memory_vars(u64 start, u64 size)
* Memory is added always to NORMAL zone. This means you will never get
* additional DMA/DMA32 memory.
*/
-int arch_add_memory(int nid, u64 start, u64 size, bool for_device)
+int arch_add_memory(int nid, u64 start, u64 size, enum memory_type type)
{
struct pglist_data *pgdat = NODE_DATA(nid);
- struct zone *zone = pgdat->node_zones +
- zone_for_memory(nid, start, size, ZONE_NORMAL, for_device);
unsigned long start_pfn = start >> PAGE_SHIFT;
unsigned long nr_pages = size >> PAGE_SHIFT;
+ bool for_device = false;
+ struct zone *zone;
int ret;

+ /*
+ * Each memory_type needs special handling, so error out on an
+ * unsupported type.
+ */
+ switch (type) {
+ case MEMORY_NORMAL:
+ break;
+ case MEMORY_DEVICE_PERSISTENT:
+ for_device = true;
+ break;
+ default:
+ pr_err("hotplug unsupported memory type %d\n", type);
+ return -EINVAL;
+ }
+
+ zone = pgdat->node_zones +
+ zone_for_memory(nid, start, size, ZONE_NORMAL, for_device);
+
init_memory_mapping(start, start + size);

ret = __add_pages(nid, zone, start_pfn, nr_pages);
@@ -946,7 +964,7 @@ kernel_physical_mapping_remove(unsigned long start, unsigned long end)
remove_pagetable(start, end, true);
}

-int __ref arch_remove_memory(u64 start, u64 size)
+int __ref arch_remove_memory(u64 start, u64 size, enum memory_type type)
{
unsigned long start_pfn = start >> PAGE_SHIFT;
unsigned long nr_pages = size >> PAGE_SHIFT;
@@ -955,6 +973,19 @@ int __ref arch_remove_memory(u64 start, u64 size)
struct zone *zone;
int ret;

+ /*
+ * Each memory_type needs special handling, so error out on an
+ * unsupported type.
+ */
+ switch (type) {
+ case MEMORY_NORMAL:
+ case MEMORY_DEVICE_PERSISTENT:
+ break;
+ default:
+ pr_err("hotplug unsupported memory type %d\n", type);
+ return -EINVAL;
+ }
+
/* With altmap the first mapped page is offset from @start */
altmap = to_vmem_altmap((unsigned long) page);
if (altmap)
diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h
index 134a2f6..c3999f2 100644
--- a/include/linux/memory_hotplug.h
+++ b/include/linux/memory_hotplug.h
@@ -13,6 +13,26 @@ struct mem_section;
struct memory_block;
struct resource;

+/*
+ * When hotplugging memory with arch_add_memory(), we want more information on
+ * the type of memory we are hotplugging, because depending on the type of
+ * architecture, the code might want to take different paths.
+ *
+ * MEMORY_NORMAL:
+ * Your regular system memory. Default common case.
+ *
+ * MEMORY_DEVICE_PERSISTENT:
+ * Persistent device memory (pmem): struct page might be allocated in different
+ * memory and architecture might want to perform special actions. It is similar
+ * to regular memory, in that the CPU can access it transparently. However,
+ * it is likely to have different bandwidth and latency than regular memory.
+ * See Documentation/nvdimm/nvdimm.txt for more information.
+ */
+enum memory_type {
+ MEMORY_NORMAL = 0,
+ MEMORY_DEVICE_PERSISTENT,
+};
+
#ifdef CONFIG_MEMORY_HOTPLUG

/*
@@ -104,7 +124,7 @@ extern bool memhp_auto_online;

#ifdef CONFIG_MEMORY_HOTREMOVE
extern bool is_pageblock_removable_nolock(struct page *page);
-extern int arch_remove_memory(u64 start, u64 size);
+extern int arch_remove_memory(u64 start, u64 size, enum memory_type type);
extern int __remove_pages(struct zone *zone, unsigned long start_pfn,
unsigned long nr_pages);
#endif /* CONFIG_MEMORY_HOTREMOVE */
@@ -276,7 +296,7 @@ extern int add_memory(int nid, u64 start, u64 size);
extern int add_memory_resource(int nid, struct resource *resource, bool online);
extern int zone_for_memory(int nid, u64 start, u64 size, int zone_default,
bool for_device);
-extern int arch_add_memory(int nid, u64 start, u64 size, bool for_device);
+extern int arch_add_memory(int nid, u64 start, u64 size, enum memory_type type);
extern int offline_pages(unsigned long start_pfn, unsigned long nr_pages);
extern bool is_memblock_offlined(struct memory_block *mem);
extern void remove_memory(int nid, u64 start, u64 size);
diff --git a/include/linux/memremap.h b/include/linux/memremap.h
index 9341619..1f720f7 100644
--- a/include/linux/memremap.h
+++ b/include/linux/memremap.h
@@ -41,12 +41,14 @@ static inline struct vmem_altmap *to_vmem_altmap(unsigned long memmap_start)
* @res: physical address range covered by @ref
* @ref: reference count that pins the devm_memremap_pages() mapping
* @dev: host device of the mapping for debug
+ * @type: memory type see MEMORY_* in memory_hotplug.h
*/
struct dev_pagemap {
struct vmem_altmap *altmap;
const struct resource *res;
struct percpu_ref *ref;
struct device *dev;
+ enum memory_type type;
};

#ifdef CONFIG_ZONE_DEVICE
diff --git a/kernel/memremap.c b/kernel/memremap.c
index 07e85e5..6b4505d 100644
--- a/kernel/memremap.c
+++ b/kernel/memremap.c
@@ -248,7 +248,7 @@ static void devm_memremap_pages_release(struct device *dev, void *data)
align_size = ALIGN(resource_size(res), SECTION_SIZE);

mem_hotplug_begin();
- arch_remove_memory(align_start, align_size);
+ arch_remove_memory(align_start, align_size, pgmap->type);
mem_hotplug_done();

untrack_pfn(NULL, PHYS_PFN(align_start), align_size);
@@ -326,6 +326,7 @@ void *devm_memremap_pages(struct device *dev, struct resource *res,
}
pgmap->ref = ref;
pgmap->res = &page_map->res;
+ pgmap->type = MEMORY_DEVICE_PERSISTENT;

mutex_lock(&pgmap_lock);
error = 0;
@@ -363,7 +364,7 @@ void *devm_memremap_pages(struct device *dev, struct resource *res,
goto err_pfn_remap;

mem_hotplug_begin();
- error = arch_add_memory(nid, align_start, align_size, true);
+ error = arch_add_memory(nid, align_start, align_size, pgmap->type);
mem_hotplug_done();
if (error)
goto err_add_memory;
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index a07a07c..d1a4326 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -1384,7 +1384,7 @@ int __ref add_memory_resource(int nid, struct resource *res, bool online)
}

/* call arch's memory hotadd */
- ret = arch_add_memory(nid, start, size, false);
+ ret = arch_add_memory(nid, start, size, MEMORY_NORMAL);

if (ret < 0)
goto error;
@@ -2188,7 +2188,7 @@ void __ref remove_memory(int nid, u64 start, u64 size)
memblock_free(start, size);
memblock_remove(start, size);

- arch_remove_memory(start, size);
+ arch_remove_memory(start, size, MEMORY_NORMAL);

try_offline_node(nid);

--
2.9.3